I'm sure this post will not be the end all to your problems, but perhaps open another train of thought on something to possibly consider. I've recently been toying around with the timing, point gap, A/F ratios and plug heat range on my bike with interesting results.
Today I spent about four hours with a timing light to see what configurations did what and how the results were. Perplexed, frustrated, awed and the like, it was an interesting day.
From what I understand, and this is on my 400, you first must check the tappet clearance. Then you check the point clearances (which is horribly delicate IMO). After these two things, you can start medling with the timing. Say all that stuff is good.
First you want to take your timing light and put it on either the #1 or #4 spark plug wire. Set your idle to 1100RPM (it must be a stable idle) then check to see if the F mark lines up with the static line with the light. Remember there is a slight delay between the firing and timing of the engine. Adjust the timing as necessary. After this, you put the timing light on either #2 or #3 wire and check the timing of this. You adjust the plate as necessary and tighten down the three retaining screws.
Once this is done, stand up and grab the throttle and twist it to 2500RPM. Bend back down while trying to hold the throttle open at 2500RPM and recheck the timing on #2 and #3 to see if everything still lines up. The F line should still line up.
On my bike, the timing is set so that the static line on the crank case is just to the right side of the left most line on the plate. I'd say 1mm to the right of it.
Hope this helps. Good luck. I know it can be a PITA for sure. I hope I didn't leave anything out.
